Generally, a radar system has been applied to various technical fields. Here, the radar system is mounted on a vehicle so that a mobility of the vehicle is improved. Such a radar system detects information on the surroundings of the vehicle using an electromagnetic wave. Further, as the vehicle uses the information for the movement thereof, its mobile efficiency may be improved. For this, the radar system includes an antenna device. That is, the radar system transmits and receives an electromagnetic wave through the antenna device. Here, the antenna device includes multiple radiators. Here, the radiators are formed in a certain size and shape.
However, the antenna device of the radar system has a problem that the performances of the radiators are not uniform. It is because environmental factors such as a loss rate occur differently in the antenna device depending on the location of the radiators. Additionally, the antenna device of the radar system has a problem that it has a limited detection coverage only. Due to this, it is difficult for the radar system having a single antenna device to detect information on a wide detection coverage. Also, when the radar system includes a number of antenna devices, the radar system may be enlarged in size and its cost may be increased.